Event Calendar

Lectures & Seminars

16.11.2017 14:00 - 15:00 o'clock


Scientific seminar: Induction of bronchus-associated lymphoid tissue by E. coli, and establishment of a method for its analysis in whole mouse lung lobes

Lecturer: Dr. David Mzinz, Institute of Immunology, Hannover Medical School

Abstract:

David T. Mzinza, Henrike Fleige, Kristin Laarmann, Stefanie Willenzon, Jasmin Ristenpart, Julia Spanier, Gerd Sutter, Ulrich Kalinke, Peter Valentin-Weigand, Reinhold Förster

Bronchus-associated lymphoid tissue (BALT) plays an important role in initiating and maintaining host protective immunity against pathogens. It is not constitutively found in most species, but can be induced when the lung is exposed to some microorganisms or compounds that cause lung inflammation. Development of microorganism-induced BALT is driven by different molecular mechanisms. Two pathways have been identified so far; one that relies on the presence of IL-17 (e.g. P. aeruginosa), and another which does not (e.g. MVA). To further understand BALT development and function, additional studies that characterize its induction by other microorganisms are needed. Currently, BALT is primarily investigated by immunohistology. However, this approach might not reflect the composition of BALT in the entire lung since only a limited number of sections can be analyzed. Additional approaches to study BALT in the entire lung are needed.
Here we present data on characterization of E. coli-induced BALT in mice. Mice administered with one dose of heat-inactivated lab strain, DH5?, of E. coli developed BALT characterized by the presence of organized B cell follicles accompanied by T cells, FDCs expressing CXCL13 as well as other CXCL12-expressing stroma cells. Furthermore, we established the application of light sheet microscopy (LiSM) for analysis of BALT in mice lung lobes. BALT was identified by antibody-staining of its constituent T and B cell aggregates. Prior to imaging, lobes were optically cleared using a protocol previously described by Ertürk et al. in 2012, called 3DISCO. BALT within LiSM imaged lobes was analyzed with Imaris software. Using this approach we could show the entire lung’s bronchial tree, the frequency of lymphocyte aggregates, as well as the volume of BALT within the entire lobes from uninfected or BALT-bearing mice. Interestingly, when using mice lacking the chemokine receptor CXCR5, we could show that E. coli-induced BALT is dominated by T cell aggregates. This is the first study that describes the induction of BALT by a single intranasal dose of E. coli and identifies chemokines and chemokine receptors involved in this process. These results might help to understand E. coli-specific immune responses, hence contribute to the development of strategies to control its associated infections. Moreover, the application of LiSM on whole lung lobes provides essential new insights in lung architecture as well as in understanding the development and organization of lymphoid aggregates within the whole lung under different conditions.

Date: November 16th 2017

Time: 2 pm

Location: Lecture hall Robert Koch, HKI Jena

All interested are cordially invited!

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